Story Card, Head Of The Shaft Works
The Miners’ CaveIn 1826 this was the most famous building site in the world, to which thousands of people came to see a monumental work in progress.
The Brunels built a 50 foot tower and then sunk it by degrees into the soft earth.
It is the world’s first caisson, using a method that is now used in every country. Steam engines worked constantly to pump out water from the tunnel, while the men were lowered down the small shaft that can be seen in the foreground.
The building on the left has a criss cross bas-relief design in brick and timber.
Marc Brunel used this illustration to invoke the scale of the work under the Thames.The miners laboured in small cages or compartments just below the riverbed, part of a great iron tunnelling shield.
Each compartment of the shield was protected by planks held in place by jack screws.
The miner would remove one of the planks, dig out four inches of clay, and then put the plank back in place; this exercise was repeated until the whole area in front of the cage had been excavated, whereupon the cage was then jacked forward.
Another small section of the tunnel was completed.
The bricklayers working behind the miner then built the walls. As they worked the miners were showered with Thames water, which was often as not raw sewage.
They also were threatened by fire; their oil lamps ignited the pockets of methane or marsh gas that developed in the confined space of the tunnel.
They inched their way under the Thames, and towards the end of the project worked only in two-hour shifts.
This was not the result of wise or compassionate management; at the end of two hours, they often collapsed. Many were carried out senseless, while others were taken to the local asylum where they might or might not recover.
It was a brutal and fearful business but by these means Brunel helped to fashion a system that is in use all over the world.
The underground or tube system could not have been created without his precedent. He was indeed a lord of the underworld.